Research evidencing the consequences of the experience of ‘calling’ have multiplied in recent years. At the same time, concerns have been expressed about the conceptual coherence of the notion as studies have posited a wide variety of senses in which both workers and scholars understand what it means for workers to be called, what they are called to do and who is doing the ‘calling’. This paper makes both conceptual and empirical contributions to the field. We argue that Bellah et al.’s (Habits of the heart: Individualism and commitment in American life, University of California Press, 1996) contrast between tradition-based and expressivist understandings of ‘calling’ highlights a fundamental but neglected fissure in the literature. Expressivist accounts amongst both scholars and research participants require only that ‘calling’ be deeply felt by those who experience it. However, tradition-based accounts require an external caller. Exemplifying this, workers who attest to a divine call and scholars who write about ‘calling’ in the context of particular Christian traditions understand ‘calling’ in terms of a relationship with God. These accounts cannot but be in radical tension. We suggest that this conceptual confusion can be understood in terms of MacIntyre’s notion of ‘tradition-constituted rationality.’ The implications of this argument for practice are evidenced in our report of a study of adherents to one such tradition, workers at a Christian organization that supports people in poverty. Through in-depth interviews with long-term volunteers, we seek to assess if tradition-based ‘calling’ can be evidenced in unpaid work for the lack of pay and career progression opportunities strongly suggest the presence of ‘calling.’ This study demonstrates that even in the context of work that exhibits duty and altruism associated with expressivist accounts of ‘calling,’ these workers’ understanding of the relationships between themselves, their clients and Jesus Christ dominate their work choices. It is the meaning derived from a divine caller, understood in terms of Christian tradition, that accounts for their decision to begin and to continue this work.